Fluid sprinkling – spraying – and diffusing – Processes – Vibratory or magneto-strictive projecting
Reexamination Certificate
2001-01-08
2003-01-21
Evans, Robin O. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
Processes
Vibratory or magneto-strictive projecting
C239S001000, C239S005000, C239S102100, C239S102200
Reexamination Certificate
active
06508411
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of driving a liquid-drop spraying device for use in various kinds of machines for processing the above described liquid-drop by means of discharging the liquid-drop. The present invention is particularly useful as a liquid discharging device upon drying process of various liquid raw materials which are required for stable liquid discharges, and is preferable as a discharging device for various liquid, such as a liquid discharging device upon drying a solution including product aiming at supplying reactive raw materials such as pharmaceutical synthesis and powder production.
2. Description of the Prior Art
As for a conventional method of driving a liquid-drop spraying device, in a driving device for a liquid-drop spraying device comprising a plurality of minimal liquid-drop discharge units having respectively pressure means for discharging a liquid, a pressurized room for pressurizing discharge liquid, a nozzle for liquid discharge connected to the pressurized room, an inlet hole for supplying a liquid into the pressurized room, the foregoing inlet holes for supplying liquid of a plurality of liquid drop discharge units adjacent to each other being connected through a common liquid supplying path, and having the relevant piezoelectric\electrostriction element in a portion of a wall portion of the relevant liquid pressurized room, there has been a conventional method of driving a liquid-drop spraying device, in which the wall portion of the relevant liquid pressurized room is deformed by applying a predetermined voltage signal (charging or discharging) to the relevant piezoelectric\electrostriction element, hence, a liquid supplied to the relevant liquid pressurized room is sprayed from the foregoing nozzle by the pressure produced in the relevant liquid pressurized room, and a liquid is supplied from the inlet hole to the pressurized room by recovering the distortion of the relevant liquid pressurized room to the original form.
Then, depending upon a kind of liquid drop processing device mounted on a liquid drop spraying device, there is a device for use in supplying a large amount of liquid, a large amount of liquid is supplied by enlarging aperture of a nozzle hole and inlet hole.
However, in the case where an aperture of a nozzle hole is made too large, discharging liquid cannot be a minimal liquid-drop. Neither, as for an inlet hole, since an inlet hole not only has a function as a path through which the liquid is supplied into the pressurized room, but also has a function preventing back flow even if pressurized at the time when a liquid is sprayed from nozzle hole, the aperture of the hole cannot be widened to unlimited. Therefore, although the number of times of application per unit time period is increased and an amount of supplying volume of liquid is increased by shortening an interval time period of applying a predetermined voltage signal to piezoelectric\electrostriction element, since liquid supply from an inlet hole to a pressurized room is delayed, it cannot be carried out to stably supply a larger amount of the liquid.
DISCLOSURE OF THE INVENTION
As for a method of driving a liquid-drop spraying device according to the present invention, in a liquid-drop spraying device comprising a plurality of minimal liquid-drop discharge units respectively having a nozzle for liquid discharge, a pressurized room for pressurizing a liquid made discharge from the relevant nozzle, an inlet hole supplying a liquid into the relevant pressurized room and piezoelectric\electrostriction element making the relevant pressurized room pressurize and operate, the foregoing liquid inlet holes of a plurality of liquid-drop discharge units being connected to a common liquid supplying path, a method of driving a liquid-drop spraying device according to the present invention is provided, in which a wall portion of the foregoing pressurized room is deformed by repeatedly applying a predetermined voltage signal to the foregoing piezoelectric\electrostriction element, thereby spraying a liquid supplied into the relevant pressurized room from the foregoing nozzle by the pressure produced in the pressurized room, characterized in that the ratio of the foregoing inlet hole aperture to the foregoing nozzle hole aperture (inlet hole aperture
ozzle hole aperture) ranges from equal to or more than 0.6 to equal to or less than 1.6, and the ratio of the nozzle hole aperture and the nozzle thickness (nozzle hole aperture
ozzle thickness) ranges from equal to or more than 0.2 to equal to or less than 4, after the foregoing applying voltage signal supplies and charges the current from starting charge voltage to the foregoing piezoelectric\electrostriction element, retaining final charge voltage during certain time period, and then discharges having more than 2 kinds of discharge time constants are in turn performed, and the initial first discharge time constant is larger than the next second discharge time constant, making the foregoing starting charge voltage as a reference, the second discharge is started with voltage ranges from equal to or more than 35% to equal to or less than 70% of voltage difference between the foregoing starting charge voltage and the foregoing final charge voltage.
The present invention effectively acts when discharging on a liquid having a low viscosity, concretely, a liquid having a viscosity of 0.2 mPa/S-30 mPa·S, preferably a liquid having a viscosity of 0.5 mPa/S-1.2 mPa/S, in the case where liquid-drops are discharged from a plurality of liquid-drop discharge units at the same time according to the above described constitution, when a liquid is supplied from a liquid inlet hole into a liquid pressurized room after liquid discharge, since it performs rapidly suctioning the liquid having started to move than at the first suction speed and smoothly supplying the liquid and in a short time into the liquid pressurized room after first comparatively slowly suctioning the liquid and flowing the liquid into the whole inlet holes, a stable discharge of liquid can be carried out without producing bubbles in the liquid of the liquid pressurized room as well as an amount of liquid supplying per unit time period is increased.
Moreover, rapid pressure variation within pressurized room is avoided by retaining final charge voltage during certain time period immediately after discharging liquid-drop and that bubbles entering into a pressurized room from a nozzle by vibration of liquid level in a nozzle for liquid discharge is avoided, but immediately after starting discharge voltage, liquid vibration in a nozzle for liquid discharge is still remained. Hence, during the foregoing vibration is remained, discharge time constant is made larger, then suctioning the liquid by slow pressure variation, consequently when the foregoing vibration has been attenuated, if discharge is rapidly performed at the second discharge time constant, entrainment of bubbles from the nozzle for liquid discharge into the pressurized room by pressure variation of discharge time can be prevented, time interval of applying a predetermined voltage signal can be shortened to piezoelectric\electrostriction element and an amount of liquid supply can be increased since discharge at the second discharge time constant is rapidly performed.
Furthermore, voltage starting discharge at the second discharge time constant is preferably made ranged from equal to or more than 35% to equal to or less than 70% of voltage difference between starting charge voltage and final charge voltage, making starting discharge voltage as a reference.
When the starting discharge voltage is equal to or less than 35%, since discharge whose discharge time constant is large, i.e., suction which is slowly performed occupies most of all suctioning steps, suction itself is securely performed, however, an amount of suction per unit time period is not taken large, since a discharge period cannot be shortened as a result, a larg
Hirota Toshikazu
Ohnishi Takao
Ohwada Iwao
Burr & Brown
Evans Robin O.
NGK Insulators Ltd.
LandOfFree
Method of driving liquid-drop spraying device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of driving liquid-drop spraying device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of driving liquid-drop spraying device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3008593